In some situations, it is preferable to filter only the shadow areas of images leaving bright areas intact. You can do this with the standalone Neat Image by using the noise profile equalizer to limit or stop filtration of bright image areas.
The noise profile equalizer sliders correspond to particular ranges of brightness (individually for each color channel) of the RGB color space. The position of each slider changes (fine-tunes) parameters of the noise profile for the corresponding range of brightness. The lower a slider, the less filtration will eventually be applied to image elements that belong to the corresponding range of brightness.
Therefore, to filter only shadows you can manually move all the 'bright' sliders down (refer to the gradients in the bottom of noise profile equalizer). For example, move down all but the three 'darkest' sliders in each RGB channel.
Using this method, you can effectively prevent filtration of the bright image areas.
If you use the plug-in version of Neat Image, you can filter shadows/lights only using the selection capabilities of your image editor. Select an area to be processed (for example, select shadows based on low brightness values) and invoke Neat Image plug-in to filter this area.